Codice Performante in C++ per R

foo.cpp

  #include <Rcpp.h>
  using namespace Rcpp;
  // [[Rcpp::export]]
  NumericVector timesTwo(NumericVector x) {
    return x * 2;
  }

library(Rcpp)
sourceCpp("foo.cpp")
timesTwo(2)

## [1] 4

RcppArmadillo Uso di Rcpp con la libreria di linear algebra in C++ Armadillo

  #include <RcppArmadillo.h>

RcppGSL interfaccia a GNU GSL

  #include <RcppGSL.h>
  #include <gsl/gsl_matrix.h>
  #include <gsl/gsl_blas.h>

RcppSMC implementa Rcpp per Sequential Monte Carlo and Particle Filters (SMC)

  #include <RcppParallel.h>

#include <Rcpp.h>
using namespace Rcpp;

#include <algorithm>

// [[Rcpp::export]]
double vectorSum(NumericVector x) {
  return std::accumulate(x.begin(), x.end(), 0.0);
}

// [[Rcpp::depends(RcppParallel)]]
#include <RcppParallel.h>
#include <Rcpp.h>
using namespace RcppParallel;
struct Sum : public Worker
{   
  // source vector
  const RVector<double> input;
  // accumulated value
  double value;
  // constructors
  Sum(const Rcpp::NumericVector input) : input(input), value(0) {}
  Sum(const Sum& sum, Split) : input(sum.input), value(0) {}
  // accumulate just the element of the range I've been asked to
  void operator()(std::size_t begin, std::size_t end) {
    value += std::accumulate(input.begin() + begin, input.begin() + end, 0.0);
  }
  // join my value with that of another Sum
  void join(const Sum& rhs) { 
    value += rhs.value; 
  }
};

using namespace RcppParallel;
// [[Rcpp::export]]
double parallelVectorSum(Rcpp::NumericVector x) {
  // declare the SumBody instance 
  Sum sum(x);
  // call parallel_reduce to start the work
  parallelReduce(0, x.length(), sum);
  // return the computed sum
  return sum.value;
}

library(RcppParallel)
sourceCpp("foo_ser.cpp")
sourceCpp("foo_par.cpp")
library(rbenchmark)
v <- as.numeric(c(1:10000000))
pp <- benchmark(vectorSum(v),parallelVectorSum(v),order="relative")
pp

##                   test replications elapsed relative user.self sys.self
## 2 parallelVectorSum(v)          100   0.418    1.000     1.483    0.009
## 1         vectorSum(v)          100   1.181    2.825     1.166    0.005
##   user.child sys.child
## 2          0         0
## 1          0         0

R embedded in classi C++

  #include <RInside.h>

Pacchetto giovane, alle versione 0.2, ma promettente …

#include <RInside.h>   // for the embedded R via RInside

int main(int argc, char *argv[]) {

    RInside R(argc, argv);  // create an embedded R instance

    R["txt"] = "Hello, world!\n";   // assign a char* (string) to 'txt'

    R.parseEvalQ("cat(txt)"); // eval the init string, ignoring any returns

    exit(0);
}

Widgets interattivi costruiti con R e javascript Già ci sono alcuni paccheti di R che implementano librerie js

esempi con questo dataset

Scaricamenti prari di pacchetti R per nazione

m_hours_countries[1:4,1:10]

##       AR AT  AU BE  BR  CA CH CL   CN CO
## 00:00 24  2 191  3 115 136  3  9 3045 55
## 01:00 21  1 188  1  84 118  5 25 3300 48
## 02:00 18  0 143  1  65 135  2 13 3698 42
## 03:00 13  2 152  0  41 102  4 12 3252 34

Libreria per serie temporali

Heatmap usando D3

library(d3heatmap)
m_counts <- t(acast(counts, date ~ hour, value.var = 'n'))
d3heatmap(scale(m_hours_countries), cellnote = m_hours_countries,
  colors = "Blues", dendrogram = "col")

Mappe interattive

library(leaflet)
leaflet(quakes) %>%
  addTiles("https://api.tiles.mapbox.com/v4/mapbox.wheatpaste/{z}/{x}/{y}.png?access_token=pk.eyJ1Ijoic2FudG9yb21hIiwiYSI6ImUxN2ZkZWRkNTU2NjVlZjRiM2E2ZmZhNGQyODM0OGFhIn0.mM32XaR8Ro0dBQIlA6G2iA") %>%
  addCircles(color = "#CC0000", weight = 2, radius = ~10^mag / 5,
    popup = ~as.character(stations))

Mappe interattive

## Assuming 'long' and 'lat' are longitude and latitude, respectively

Libreria 3D in javascript

library(threejs)
globejs(lat = quakes$lat, long = quakes$long, 
        value = 10^quakes$mag / 10^4,atmosphere = TRUE)

Tree Viewer in js D3

# devtools::install_github("sdwfrost/epiwidgets")
library(epiwidgets)
nwk <- "(((EELA:0.150276,CONGERA:0.213019):0.230956,(EELB:0.263487,CONGERB:0.202633):0.246917):0.094785,((CAVEFISH:0.451027,(GOLDFISH:0.340495,ZEBRAFISH:0.390163):0.220565):0.067778,((((((NSAM:0.008113,NARG:0.014065):0.052991,SPUN:0.061003,(SMIC:0.027806,SDIA:0.015298,SXAN:0.046873):0.046977):0.009822,(NAUR:0.081298,(SSPI:0.023876,STIE:0.013652):0.058179):0.091775):0.073346,(MVIO:0.012271,MBER:0.039798):0.178835):0.147992,((BFNKILLIFISH:0.317455,(ONIL:0.029217,XCAU:0.084388):0.201166):0.055908,THORNYHEAD:0.252481):0.061905):0.157214,LAMPFISH:0.717196,((SCABBARDA:0.189684,SCABBARDB:0.362015):0.282263,((VIPERFISH:0.318217,BLACKDRAGON:0.109912):0.123642,LOOSEJAW:0.397100):0.287152):0.140663):0.206729):0.222485,(COELACANTH:0.558103,((CLAWEDFROG:0.441842,SALAMANDER:0.299607):0.135307,((CHAMELEON:0.771665,((PIGEON:0.150909,CHICKEN:0.172733):0.082163,ZEBRAFINCH:0.099172):0.272338):0.014055,((BOVINE:0.167569,DOLPHIN:0.157450):0.104783,ELEPHANT:0.166557):0.367205):0.050892):0.114731):0.295021)"
treewidget(nwk)

Tree Viewer in js D3

library(tmap,quietly = T,warn.conflicts = F)
data(World)
data(metro)
qtm(World, fill="pop_est_dens", theme="World", fill.style="kmeans", 
    fill.title="Population per km^2") +
  qtm(metro, bubble.size = "pop2010", bubble.col ="purple", 
      bubble.title.size="Metropolitan Areas", theme = "World", bubble.scale=.5)